The broad objective of the proposed research is to understand how people's sense of power influences the domains which they base their self-esteem, as well as the consequences for psychological health and behavior. Specifically, this research tests the novel hypothesis that low power leads individuals to base their self-esteem in being morally upstanding whereas high power leads to basing self-esteem in being competent and skillful. As a consequence, the psychological health and well-being-self-esteem, positive and negative affect, life satisfaction, depressive symptoms-of low-power individuals comes to depend on perceptions of whether or not the self is moral (rather than competent). By contrast, the psychological health and well-being of high-power individuals comes to depend on perceptions of the self's level of competence, rather than morality. Moreover, power differences in bases of self-esteem are expected to shape behavior. Motivated by the need to enhance a sense of morality, it is anticipated that low-power individuals will preferentially select personal goals and activities that reflect attempts to live up to a moral code (e.g., volunteering, donating to charity). Motivated by the need to enhance a sense of competence, high-power individuals will pursue goals and activities that reflect an attempt to sharpen skills and abilities. For similar reasons, it is further expected that, paradoxically, low-power individuals may at times behave more anti- socially than high-power individuals-namely when doing so counteracts threats to the moral self-image. In this situation, low-power individuals may be particularly quick to resent, derogate, and sabotage the morality of an individual who has recently made the self appear immoral by comparison. The proposed research will employ diverse methodologies, including a longitudinal study of individual differences, experimental manipulations of power, and observation of behavior during social interaction. The project advances the NICHD's mission to ensure the health, well-being and flourishing of individuals in several ways. It aims to reveal how power dynamics-a pervasive characteristic of social life-and bases of self-esteem factor into a variety of psychological health and well-being indicators (e.g., depression, life satisfaction), and into behaviors relevant to human flourishing and development, such as life goal pursuit. Furthermore, the expected results may help improve psychological services, for example, by suggesting that providers take into account how opportunities for self-esteem and well-being differ as a function of power. Finally, by advancing scientific knowledge about factors that determine levels of self-esteem, this research has implications for understanding and changing the multiple mental, physical and public health issues known to be influenced by self-esteem, including psychological disorders, physical illnesses, and rates of aggression, prosocial behavior and criminal activity.1-4